Lock-in amplifiers

the long version

This book was written for all users of lock-in amplifier equipment and for those with an interest in the practical aspects of signal recovery and measurement using synchronous detection. Among the topics included are the principles of phase-sensitive detection, applications for two-phase lock-in amplifiers, the problems of phase-locking to very noisy signals, a review of system configurations for heterodyne and PWM lock-in amplifiers and the use of lock-in amplifiers in computer-controlled measurements. The numerous appendices cover selected topics in signal and noise theory, the principles and practice of amplifier noise-matching and techniques to combat interference and ground loops. The material is presented at systems level throughout and it is intended that the treatment will prove both interesting and useful to specialists and generalists alike. The PDF version has been newly compiled from the original typescript and diagrams with minor corrections but no substantial changes to the original text.